Prestress-dependent propagation of forces to the nucleolus

We quantified displacements of nucleolar structures in cultured interphase cells in response to a localized physiologic oscillatory load via a magnetic bead. The computed size and shape deformations of nucelolar structures exhibited heterogeneous patterns. The peak displacements of the nucleolus decayed much slower in distance from the load than conventional homogeneous models predict. Increasing the pre-existing tensile stress (prestress) in the cytoskeleton (CSK) significantly increased the stress propagation efficiency to the nucleolus whereas decreasing the prestress significantly lowered the stress propagation efficiency to the nucleolus. These results demonstrate that the prestress in the CSK is crucial in mediating stress propagation to the nucleolus.